The
Liber Pontificalis, the official collection of papal
biographies, as well as other Church histories, provides
considerable information on the development of election law. As
this summary shows, it was often developed in the crucible of
trial, as the Church sought to fend off, or at least moderate,
external influences on the election process.

Fabian divided
the Roman See into 7 deaconal regions. The deacons who
administered these regions, together with the 7 deacons
who were the assistants to the Pope, were the forerunners
in office of the Cardinals who have diaconal rank today.

336

Pope Mark
establishes the Bishop of Ostia as the principal
consecrator of the newly elected Pope. At this time in
history the popes typically came from among the priests
and deacons of Rome, and thus had to be consecrated a
bishop in order to assume office.

420

Boniface I
(418-22) obtains the agreement of Emperor Honorius that in
a disputed election (such as his was), both electees would
be rejected. The civil authorities would be obliged to
recognize a unanimous electee. The interference of Emperor
Honorius in the election of Pope Boniface was the first in
Church history, but not the last. Likewise, this agreement
would not be the last attempt to ensure the freedom of the
election and the tranquility of the passing of papal
authority.

499

Symmachus
(498-514) calls a Roman Synod which decrees as he wished
that only the clergy of Rome will vote in an election and
the majority candidate wins. Such election would occur if
the previous Pope did not designate his successor.

607

Boniface III
(607) calls a Roman Synod which reinforces the prohibition
of electioneering and bribery. It also establishes a 3 day
wait for the election after the death of a Pope. It also
permitted the participation of the nobility, along with
the clergy.

741

After Gregory
III (731-41) Popes no longer though it necessary to seek
the concurrence of the Emperor in Constantinople. While no
Pope had thought it a theological necessity it had become
a practical one for election. However, it was one under
which the Bishop of Rome chaffed. Often the Emperors had
their pet heresies which Rome resisted as heterodox, and
the process of seeking his consent, or that of his
representative in Ravenna, often delayed the inauguration
of the pontificate by weeks or even months. Eventually,
the emperor's problems in the East with Islam effectively
liberated the Pope from the need for his approval.

769

Stephen III (IV)
sought to restrict the electors of the Pope. Acting
through a Roman Synod it was decreed that only cardinal
priests and cardinal deacons could be papal electors. At
this time in history the cardinals actually held
the offices which today are only titular. Thus, the
priests and deacons in question were the actual pastors of
principal Roman churches and deacons who administered
Roman districts. The role of the laity and nobility was
restricted to confirming the election.

800

Leo III crowns
King Charles (Charlemagne) of the Franks, Holy Roman
Emperor, re-establishing the Western empire.

824

The Co-Emperor
Lothair insisted on the rights of all Romans, clerical and
lay, to participate in papal elections. The emperor would
not interfere in the election, but would require an oath
of allegiance to himself of the electee.

861

Nicholas I,
acting through a Roman Synod, condemned those who
denied the election of the Bishop of Rome by its clergy
and nobility alone.

898

John IX at the
Synod of Rome decrees that in the future the Pope will be
elected by the cardinal bishops, cardinal priests and
cardinal deacons. The rights of the nobility and people
were protected by requiring the election to take place
publicly.

962

John XII agrees
to the Ottonian Privilege, which required the Pope to take
an oath of loyalty to the Holy Roman Emperor, Otto at that
time, in exchange for his protection and non-interference
in papal elections.

1059

Nicholas II, in
the synodal decree In nomine domine establishes
that only cardinal bishops will elect the pope, and then,
as a usual matter, from among the Roman clergy. The
cardinal priests and deacons would then be asked to give
their consent. Finally, consent would be sought from the
people. The emperor could confirm the Pope, but this was a
privilege, not a right.

1073

Gregory VII
(Hildebrand) began the fight against the practice of
investiture, secular princes "investing" popes and
bishops with office. In this he ran head-long into
Henry IV, whom he excommunicated and unsuccessfully
deposed.

1089

Urban II grants
equal rights to cardinal priests, on par with cardinal
bishops, in the election of popes.

1122

Finally, in the
Concordat of Worms the Emperor agreed that secular princes
did not convey spiritual authority (symbolized by the
episcopal crosier and ring) to the bishops in whose
territory their diocese falls. However, they could convey
the scepter as a sign of any temporal rule that fell under
the bishops jurisdiction.

1150

Eugene III gives
the Sacred College of Cardinals canonical form, with a
Dean, who is Bishop of Ostia, and a Camerlengo, who is
administrator of property.

1163

Alexander III
allows the Archbishop of Mainz to return to his See in
Germany rather than remain in Rome, as Cardinals were
required to do. He gave him a "titular" church in Rome,
thus instituting the practice which is today the norm.

1179

The 3rd
Ecumenical Council of the Lateran, convened by Pope
Alexander III, decrees that the one elected must have
2/3rds of the votes of the Cardinals who are present.

1245

The red hat
seems to have been first granted to Cardinals under
Innocent IV.

1274

The Constitution
Ubi periculum of the 3rd Ecumenical Council of
Lyon, under Gregory X, establishes norms for the death and
election of a Pope. It decrees the cloistering of
the Cardinals and the secrecy of the Conclave behind a
double lock. The Marshal of the Conclave holds the outside
key, the Camerlengo the inside key. If an election
does not result in three days, the Cardinals are to be
have only bread, water and wine.

1276

Hadrian IV
suspends the harsh norms of Ubi periculum.

Celestine V in
Constitutionem revises and renews the norms of
Ubi periculum. He provides three means of election: 1)
2/3rds vote in a secret ballot, 2) acclamation (also
called inspiration), whereby one or more Cardinals propose
someone whom the rest accept, or 3) consensus, in which
election is achieved by mediation between blocks of votes.

1294

Boniface VIII
confirms the legislation of Celestine V and Gregory X
inserting it into the canon law decretals. He also grants
the wearing of a red cassock to Cardinals.

1353

Innocent VI
condemns and nullifies certain concessions regarding the
authority of the Cardinals agreed to during the conclave
which elected him, thus asserting the invalidity of such
bargains which attempt to restrict the authority of the
Pope.

1417

Martin V seems
to have created the first Cardinal "in pectore", that is,
without publicly naming him. Such cardinals loose their
title if not "published" prior to the Pope's death.

1431

Eugene IV
establishes that Cardinals do not receive their rank and
title until the received their insignia of office.

1464

Red biretta, red
zucchetto (skull-cap), and red mantle, began to be
bestowed on new Cardinals under Paul II.

1555

Paul IV
establishes that the most senior Cardinal residing in Rome
becomes the Dean of the College.

1563

Council of
Trent, under Pius IV, decrees that the Cardinals should be
chosen from all nations in Christendom and if they are
residential bishops they should remain in their respective
Sees rather than live in Rome.

1586

Sixtus V, in his
apostolic constitution Postquam verus decrees that
Cardinals be clerics for at least one year prior to
creation, which meant they had received all minor orders
(porter, lector, exorcist, acolyte). Further, they could
not be illegitimate sons, have any impediments for
receiving holy orders, have had children or grandchildren,
nor be the brothers, nephews, uncles, cousins, or any
relative of first or second degree, of members of the
Sacred College.

Innocent XII, in
his apostolic constitution Romanum decet Pontificem
transfers jurisdiction over the clergy and people of the
Roman churches and deaconries from the Cardinals who hold
title to the Cardinal Vicar of Rome. The Cardinals
retained some rights and privileges, however.

1695

Innocent XII, in
his apostolic constitution
Ecclesiae Catholicæ
forbade the practice of "capitulations", agreements
between the cardinals and a papabile about what he will do
after he is elected.

1724

Benedict XIII
decreed that the Cardinal Dean will be the most senior
Cardinal, irrespective of residence.

1731

Clement XII
restored the Deanship to the most senior Cardinal residing
in Rome. He also provided that precedence within the 3
ranks of Cardinals be established by seniority, seniority
of episcopal consecration for Cardinal Bishops, and
seniority of being made Cardinal for the other ranks.

1882

Leo XIII
provides for holding a papal election in extraordinary
circumstances, such as the occupation of Rome (begun in
1870 by Italian forces), through his Apostolic
Constitution Praedecessores Nostri.

1904

Pius X
establishes an excommunication for any Cardinal who would
attempt to exercise a "right of exclusion" (veto) on
behalf of a secular prince (at this time Austria, France
and Spain). He also establishes comprehensive laws
regarding the death of a Pope, the interregnum and the
election of the Pope, in the Apostolic Constitution
Vacante Sede Apostolica. Among these, the Cardinals
must wait ten days before beginning the election.

1910

Pius X
establishes suffragan bishops in the suburicarian Sees to
relieve the Cardinal Bishops of the responsibility for
daily administration.

1914

Pius X divides
the See of Velletri and Ostia and decrees that the Dean of
the College will hold the See he held at the time of
election as Dean, as well as the See of Ostia.

1915

Benedict XV
restores the full governance of the Cardinal Bishops over
the suburicarian Sees.

1917

Benedict XV
promulgates the 1917 Code of Canon Law, which
consolidates the general law of the Church. May other laws
remain separate, such as those regarding the organization
of the Roman Curia and the Death and Election of a Pope.

1922

Pius XI
establishes that the Conclave must begin fifteen days
after the death of a Pope and no later than eighteen.

1929

Pius XI signs
the Lateran Treaty with Italy. Among its provisions is the
freedom of the conclave.

1945

Pius XII, in his
apostolic constitution Vacantis Apostolicæ Sedis
repeats most of the norms promulgated by Pope Pius X.
However, he establishes a 2/3rd + 1 majority for election,
changing the norm of Lateran III (1179).

1962

Cardinals
Bishops will have title to their Sees in name only. Other
bishops will have full ordinary power in those dioceses.

1965

Paul VI decrees
in Ad purpuratorum patrum, issued motu proprio,
that Eastern-Rite Patriarchs made Cardinals will not be
given Roman title, but will retain their patriarch Sees.

1969

Paul VI's Ad
hoc usque tempus, issued motu proprio, abolishes all
administrative and governance functions of Cardinals
priests and deacons in the churches and deaconries to
which they hold title. They retain only the duty to
promote their well-being by their advice and protection.

1970

By
Ingravescentem aetatem, issued motu proprio, Paul VI
limits entry into the Conclave and voting to those
cardinals who have not yet reached 80 years of age.

1973

Paul VI limits
the number of electors to 120.

1975

Paul VI's
Apostolic Constitution Romano Pontifici eligendo
promulgates the general law for the death and election of
the Pope and the governance of the Holy See during the
vacancy. It consolidates the changes made during his
pontificate and retains the 2/3rds + 1 norm instituted by
Pope Pius XII.

1983

Pope John Paul
II promulgates the revised Code of Canon Law. As
with the 1917 Code, the general law on the death and
election of a Pope remains in particular law separately
promulgated.

1996

Pope John Paul
II promulgates the apostolic constitution Universi
Dominici Gregis. He re-establishes the 2/3rd majority
rule, and allows a simple majority under some
circumstances of a difficult election. He also establishes
the new Domus Sanctae Martha residence in the Vatican for
the exclusive use of the electors during the Conclave.

2007

Pope Benedict XVI issues an Apostolic Letter
De Aliquibus Mutationibus revoking the provision of
Universi Dominici Gregis which allowed the Electors to break
a deadlock by voting to elect by an absolute majority. The
traditional procedure by which a 2/3rds majority is required to
elect a Pope must be observed throughout the Conclave.